Talk:Solid of revolution
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Formula
[edit]This is still not right. For a start, the volume formula doesn't take into account the angle the line segment makes with the axis. -- Daran 23:31, 27 Sep 2003 (UTC)
vertical (parallel to the y-axis) for functions defined in terms of x and horizontal (parallel to the x-axis) for functions defined in terms of x. both say defined in terms of x. so what's the difference. there's something wrong with this wording. Also, How do you know which "line" to draw? Stevetek (talk) 09:42, 6 September 2008 (UTC)
I suggest to put the "rotation about the x-axis" before the other one, as it is imho the most well-known and the more simple one (direct analogy with π r² (area of circle) resp. × h (volume of cylinder). — MFH: Talk 09:50, 13 May 2005 (UTC)
Translation
[edit]The Dutch page on Solids of rev. is quite good for pictures. Can someone transfer them over here please? nl:Omwentelingslichaam . I've already put a German picture over, don't quite know what it said for the picture caption. Thanks, DavidMcKenzie 16:47, 27 February 2007 (UTC)
- Furthermore, I just noticed that the Dutch version not only gives formulas for the volume, but also for the surface. Bob.v.R (talk) 16:34, 12 December 2010 (UTC)
Definition
[edit]Current definition: revolving a curve around an axis doesn't give solid, it is the Surface of revolution. We shold revolve a planar figure instead: eg. not a circle but a disc. Faller (talk) 14:35, 4 November 2008 (UTC)
Template
[edit]Shouldn't we put the calculus template here? Nonagonal Spider (talk) 02:22, 15 November 2008 (UTC)
Center of mass
[edit]Can we add details about the center of mass formula or a link to it?
x = ∫ a b π x y 2 dx / ∫ a b π y 2 dx .
—Preceding unsigned comment added by 70.82.50.120 (talk) 15:16, 10 December 2010 (UTC)
Volume in parametric form incorrect
[edit]The article says "... the volumes of the solids generated by revolving the curve around ..." and then gives formulas. When you revolve a curve around an axis you get a surface of revolution with volume 0, not a solid. There should actually be three formulas depending on the actual area being revolved; I'll try to find a source with all three and add them when I do. --RDBury (talk) 15:26, 17 July 2015 (UTC)